Video Series: Exterior Insulation Retrofit — How To Strip Siding and Roofing

Get tips on protecting a job site, pulling off shingles, and preparing for rigid-foam insulation

with David Joyce


Narrator: The first step in an exterior foam retrofit is to strip the roofing and siding down to the bare wood. To keep the site clean and to protect the landscape, set up tarps to catch the debris.

A good way to do this is to nail a 2x4 through the tarp onto the side of the house so that nothing sneaks down behind it. If you just nail the tarp through the eyelets, they can rip pretty easily, and there aren’t really enough of them to make a good seal against the house. If garbage gets behind the tarp, it can mean damage to shrubs and more cleanup later on.

Crew member (showing roof jack): This is usually how we’ll set them, so they’re a little bit flat up there.

Narrator: At the lower edge of the roof, set up roof jacks and a 2x10 to catch anything that might fall off the roof. Most of the shingles are caught there; they can be shoveled over the side into the tarp or Dumpster.

David Joyce, Synergy Construction: Here we have the Dumpster real close by. It’s only about 10 feet away. We have nothing around it to worry about hitting or damaging.

Narrator: After the roof is stripped, inspect, repair, and clean up the roof deck. If there is any rot, replace the necessary sections of roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . Loose nails should be pulled so that they don’t work their way out, pop through the roofing membrane, and cause a potential leak. Nails that can be driven solidly into framing can be hammered home. Removing the extra nails also lowers the chances of hitting one of them later on, when fastening the thick foam with long screws. Long screws through 4 inches of foam are hard enough to drive; you’ll need all the help you can get.

Next, clean the roof deck of any sawdust or shingle debris to make a clean surface for installing the roofing underlayment. It also makes the roof a safer surface to walk on. With the roof stripped and cleaned, strip the siding. The same shingle stripping tool used on the roof works well on the wall shingles, too. Part of stripping the walls is removing all of the exterior trim, down to the window frame.

David Joyce: We removed all the exterior trim of the window. We brought it down flush with the wall, so the housewrap can come over and be connected to the window.

Narrator: Even though these windows will be replaced later, seal the housewrap to them for temporary weather protection until it’s time to replace the windows. Next, cut off the roof overhang so that there are no obstructions jutting out from the corners. When snapping a line along the roof overhang, look to see if there are any nails in the path. If so, slide the chalkline over a little bit to miss them. But use a demo blade anyway; realistically, you’ll hit a few old nails in the process.

It’s a good idea to cut back beyond the edge of the wall; so, for an 8-inch overhang, cut back about 8¼ inches. This way, even if the walls are a bit lumpy — which they often are in old houses — you’ll have a clean edge that won’t need to be trimmed later. Cutting the overhangs off makes the house a simpler shape and easier to encapsulate.

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